The field of disclosure relates generally to a low voltage drop, cross-field, gas switch and, more particularly, to a cross-field, gas switch that experiences a low forward voltage drop between an anode and cathode of the gas switch during operation thereof.
Cross-field gas switches, such as planar cross-field gas switches, are known. Conventionally, these switches include an electrode assembly, such as a cathode spaced apart from an anode, enclosed by a gas-tight chamber. The gas-tight chamber is filled with an ionizable gas, and a voltage is applied to a control grid disposed between the anode and cathode to initiate a plasma path therebetween. The switch is operable, in the presence of an input voltage applied to the anode, to conduct a large electrical current between the anode and the cathode. The plasma path may be terminated by reverse biasing the control grid, such that the electrical current flowing from the anode to the cathode is drawn off by the control grid (and accompanying circuitry). Thus, the device functions as a gas filled switch, or “gas switch” in the presence of an input voltage and a conducting plasma.
Drawbacks associated with at least some known switches include a large forward voltage drop between the anode and the cathode during conduction. Specifically, many common gas switches experience a voltage drop of several hundred volts in the gap between the anode and the cathode. The large majority of this voltage drop is experienced at or near a conduction surface of the cathode, resulting, in most cases, in thermal losses and ablation or “sputtering” of the cathode conduction surface. Sputtering tends to reduce the useful life of the gas switch, such as, for example, to a matter of hours or days in a conduction mode. Thus, conventional gas switches tend not to be feasible for large-scale, long-term, implementation in power systems where reliability, cost, and lifecycle are important considerations.
A cross-field gas switch that experiences a low forward voltage drop between an anode and cathode of the gas switch during operation is therefore desirable, particularly, where the forward voltage drop between the anode and the cathode is sufficiently low to prolong the lifespan of the device to many years, rather than, as described above, several hours or months. A gas switch that does not generate large quantities of excess thermal heat, and which does not require large heat sinking equipment, is also desirable.